Antiinflammatory compositions

ABSTRACT

Compounds having the formula:     D R A W I N G WHEREIN X is halogen and the non-toxic, pharmaceuticallyacceptable inorganic and organic salts thereof. Antiinflammatory compositions consisting essentially of at least one of said compounds in admixture with a non-toxic, pharmaceuticallyacceptable carrier. A method for reducing inflammation of the tissues in mammals comprising administering a therapeutically effective concentration of at least one of said compounds, preferably in admixture with a non-toxic pharmaceuticallyacceptable carrier.

United States Patent [191 Borne [451 Dec. 3, 1974 ANTIINFLAMMATORY COMPOSITIONS [75] Inventor: Ronald F. Borne, Oxford, Miss.

[73] Assignee: The University of Mississippi,

University, Miss.

[22] Filed: July 24, 1973 [21] App]. No.: 382,281

Related U.S. Application Data [62] Division of Ser. No. 304,485, Nov. 7, 1972, Pat. No.

[52] U.S. Cl. 424/319 [51] Int. Cl A61k 27/00 [58] Field of Search 424/319 [56] References Cited UNITED STATES PATENTS 8/1972 Shen et a1. 260/518 A Primary Examiner-Stanley J. Friedman Attorney, Agent, or FirmWil1iam D. Stokes 57' ABSTRACT Compounds having the formula:

26 Claims, No Drawings ANTIINFLAMMATORY COMPOSITIONS BACKGROUND OF THE INVENTION For a considerable period of time there has been continuing interest in the discovery and development of more effective, non-steroidal, antiinflammatory agents which can be administered to mammals in therapeutically effective dosages with minimal side effects. There is also an economic need for such agents which are relatively simple to produce from readily available, noncostly reagents.

A wide variety of compounds have demonstrated antiinflammatory properties, as for example pyrazolidinediones, arylalkanoic acids, carboxylic acid amides, and salicylates. Anthranilic acid and certain of its derivatives, such as mefenamic acid, flufenamic acid, and N-benzoyl-anthranilic acid, have also exhibited antiinflammatory activity as described, for example in the article by M. W. Whitehouse, Biochemical Properties of Anti-Inflammatory Drugs, Biochem. Pharmacol., 16, pp. 753-760 (1967). The article also discloses that N-toluenesulfonyl-anthranilic is virtually inactive as an antiinflammatory agent and postulates that this inactivity may be caused by steric hindrance of the carboxyl group by the sulfono group. However none of the known art has taught or suggested the monohalogenated N-benzene sulfonyl derivatives of aminobenzoic acid, their antiinflammatory properties, or their low degree of toxicity. In light of the prior art disclosing the inactivity of a known N-sulfono derivative, the activity of the halogenated derivatives of the invention is indeed surprising.

SUMMARY OF THE INVENTION The invention comprises new compounds having the formula:

wherein X is halogen and the non-toxic, pharmaceutically-acceptable inorganic and organic salts thereof. The carboxyl substituent is preferably in the ortho position. The halogen substituent is preferably in the para position. The preferred halogen substituents are fluorine, chlorine and bromine. Of these bromine is especially preferred.

The compounds have marked antiinflammatory activity when administered to mammals and can be given in effective, non-toxic doses. The compounds are preferably administered in admixture with a non-toxic, pharmaceutically-acceptable diluent carrier.

DESCRIPTION OF PREFERRED EMBODIMENTS The compounds are prepared as, for example, by 'reacting the mono-halogen substituted benzenesulfonyl chloride with aminobenzoic acid in dilute aqueous sodium hydroxide, acidifying the product, and then separating the resulting solid. Optimum yields are generally obtained when the pH of the basic solution of aminobenzoic acid is maintained between about 9.5 and 10.5 during addition of the substituted benzenesulfonyl chloride.

The salts can be formed by conventional techniques by reaction of the acid form of the compounds with a therapeutically-acceptable inorganic base, such as sodium, potassium, or ammonium hydroxide, or an organic base, such as an amine, e.g., methylamine, dimethylamine, triethylamine, ethanolamine, diethanolamine, triethanolamine, ethanol-diethylamine, or the like. Such salts are often preferred because of their greater solubility.

The compounds of the invention have been found to be effective as antiinflammatory agents in mammals and can be used to reduce inflammation and relieve pain in diseases such as arthritis. They can also be used to control and reduce edema.

. Treatment is preferably by oral administration of the compound in a pharmaceutically-acceptable carrier, which may be solid or liquid. Examples of acceptable solid carriers include, but are not limited to, starch, dextrose, sucrose, lactose, gelatin, agar, stearic acid, magnesium stearate, acacia and-the like. Examples of liquids include, but are not limited to, water, edible oils, such as corn or peanut oil, and the like.

When administered in solid form, the compound and diluent carrier may be in the form of tablets, capsules, powders, or lozenges prepared by standard techniques. When given as a liquid preparation, the mixture of active compound and liquid diluent carrier may be in the form ofa liquid suspension administered as such or encapsulated.

The compounds have been found to be more effective as antiinflammatory agents than the standard phenylbutazone.

When employed to treat an inflammatory condition in a mammal, animal or human, the active compound is preferably administered orally in admixture with a pharmaceutically-acceptable diluent carrier as described above. The compound is administered in a nontoxic dosage concentration sufficient to reduce the inflammation or the edema where present. The actual dosage administered will be determined by such generally recognized factors as the body weight of the patient, the severity of the condition being treated, the idiosyncrasies of the particular patient, and the activity of the specific compound employed. With these considerations in mind, the daily dosage for a particular patient can be readily determined by the medical practitioner in accordance with conventional techniques in the medicinal art.

EXAMPLE I A solution of 0.06 mole (15.3g) of pbromobenzenesulfonyl chloride in 20 ml of dioxane was added to a solution of 0.05 mole (6.9g) of anthranilic acid dissolved in 2N NaOH at such a rate as to maintain the pH between 9.5 and 10.5. After addition, the resulting solution was stirred until no further pH decrease was observed. The solution was then acidified with conc. Hcl to a pH of between 2 and 3 and vigorously stirred. The resulting solid was collected, dried, and recrystallized from ETOH-H O to give an 82 percent yield of N-p-bromobenzenesulfonyl-oaminobenzoic acid, m.p. 22l-223C. Analysis: calc. C 43.84%, H 2.84%, N 3.93%, actual C 43.83%, H 2.78%, N 3.79%.

EXAMPLE 2 The following compounds were prepared in accordance with the procedure described in Example 1:

Although this invention has been described with ref erence to illustrative embodiments thereof, it will be apparent to those skilled in the art that the principles of this invention can be embodied in other forms but 'n= No. of determinations per cone or dose level.

N-pfluorobenzenesulfonyl-o-amino-benzoic acid: 5 within the scope of the claims.

m.p. i i-173C. I claim: Analyslsl calc- 3 83 L 1. Antiinflammatory composition consisting essenacma N tially of a compound having the formula: N-p-chlorobenzenesulfonyl-o-ammobenzoic acid:

m.p. fill-203C 10 Analysis: calc. C 50.09, H 3.24. N 4.49 9w %50: HOOC Q The antiinflammation activity of the compounds prepared in Examples 1 and 2 were tested by two techniques, one an experimental in vitro technique described by J. H. Brown et al Proc. Soc. Exptl. Biol. Med., wherein a nonfmxlc 125, 837 (1967) and by the standard in vivo rat paw pharmaceutically-acceptable morgamc or organic salt edema technique described by C. A winter et A thereof in atheropeutically effective amount, in admix- PharmacoL Exp The, 141 369 (]963) ture with a non-toxic, pharmaceutically-acceptab'le The in vitro technique has been employed to screen 20 cameramiinflammatory compounds by determining their 2. The composition of claim 1 wherein the halogen ability to inhibit heat-induced hemolysis of red blood or f l 1 h h COOH cells. The procedure, as described by J. H. Brown et al, TheFomposmoll C w erem t e J supra, was followed except that fresh human blood group 15 m PP i from fasted Type 0+ donors was used rather than Tbecomposmorl P Clam 2 wherem the 'COOH blood from anesthetized mongrel dogs. Fresh human group PP l h h h blood was found to give more consistent results, possi- The PP O C W erem t e a Ogen bly due to a lack of stabilizing action of the anesthetic. 512 i, f l 2 h h h l The compounds were tested at three dose levels and p sg O C mm w erem t e aogen is m a compared to the standard phenylbutazone. Each value I is the average of 6 separate values determined as tripli- The comlgosmon of Claim 3 wherem the halogen cates on the blood of 3 to 5 separate subjects. The rem para p051 l. sults are Summarized in Table L The composition of claim 4 wherein the halogen Antiinflammatory activity was measured as inhibition 5 22 ii. f I 2 h th h l of carrageenin-induced edema in the hind paw of the is g o C aim w erem e a Ogen rat (S ra ue Dawley, 150-200 g) according to the procedur: 0% Winter et a], supra. Edema formation was h Compesmon of 4 where! the halogen measured 3 hours after an intra eritoneal injection of 1S romme' test drug suspended in saline aiid Tween 60 and 2.5 composmon of clam 6 Wherem the halogen hours after carrageenin injection. The edema inhibition 40 IS bromine of each compound (8 rats per group) was compared 12. The composition of claim 8 wherein the halogen with animals receiving only the vehicle and animals reg fi f l i 12 wh i th ceiving phenylbutazone. Each value is the average peris sol'id e Composl o c a m e e n 6 car ler 5a if flggi g fixsgzg i jfsg g m 16 to 24 rats" 14. A process for reducing inflammation in mammal 1 of the com ounds was de'termmed by the which comprises administering to said mammals the method T Litchgeld et al J pharmawl Exp compositions of claim I, said composition containing Ther 96 49) using four levels each' said compound in therapeutically-effective concentration. compound, Results are summarized in Table II. r

It will be noted that the compounds of the invention 50 F E E P claim 14 wherein the halogen were more effective than phenylbutazone in both the in vim) and in vivo assays The N 16. The process of claim 14 wherein the -COOH bromobenzenesulfonyl-o-amino-benzoic acid derivag p 15 (tho p tive showed more than twice the potency of phenylbu- Process 0 f c1a1m 15 Wherem the 'COOH tazone in the in vivo assays. This compound and the gr p 15 Oftho 9 m fluoro derivative also exhibited lower toxicity than 18. The PTOCESSOf Clalm 14 wherein the halogen phenylbutazone in a significant degree. in para position.

TABLE l Com- %lnhibition of Heat- Inhibition LDM pound Induced Hemolysis of edema Conc (11) Dose (n)" (mg/kg) F 87.8(6) 37.4(6) 179 6) 20.8624) 64.0(24) 395 Cl 66.7(6) 62.6(6) 0 (6) 35.04116) 58.1506) 275 Br 85.7(6) 30.2(6) l7.0(6) 7!.5616) anus) 385 Phenyl- 83.7(6) 35.0(6) 17.2(6) 34. (I6) 52 (I6) 336 butazone J, Ben-bassat. E. Peretz and F, G. Sulman. Arch Int. Phamacodynr Them. 122. 434 (1959).

6 I The Prom?SS of claim wherein the halogen is 23. The process of claim 17 wherein the halogen is ill P PQ bromine. The process of Claim 16 wherein the halogen i8 24. The process of claim 19 wherein the halogen is i rpara position bromine.

21. The process of claim 17 wherein the halogen is 5 The process of claim 21 wherein the halogen is in para position. bromine.

22. The process of claim 15 wherein the h l i 26. The process of claim 25 wherein the carrier is bromine. solid. 

1. ANTIINFLAMMATORY COMPOSITION CONSISTING ESSENTIALLY OF A COMPOUND HAVING THE FORMULA
 2. The composition of claim 1 wherein the halogen is F, Cl, or Br.
 3. The composition of claim 1 wherein the -COOH group is in ortho position.
 4. The composition of claim 2 wherein the -COOH group is in ortho position.
 5. The composition of claim 1 wherein the halogen is in para position.
 6. The composition of claim 2 wherein the halogen is in para position.
 7. The composition of claim 3 wherein the halogen is in para position.
 8. The composition of claim 4 wherein the halogen is in para position.
 9. The composition of claim 2 wherein the halogen is bromine.
 10. The composition of claim 4 wherein the halogen is bromine.
 11. The composiTion of claim 6 wherein the halogen is bromine.
 12. The composition of claim 8 wherein the halogen is bromine.
 13. The composition of claim 12 wherein the carrier is solid.
 14. A process for reducing inflammation in mammal which comprises administering to said mammals the compositions of claim 1, said composition containing said compound in therapeutically-effective concentration.
 15. The process of claim 14 wherein the halogen is F, Cl, or Br.
 16. The process of claim 14 wherein the -COOH group is in ortho position.
 17. The process of claim 15 wherein the -COOH group is in ortho position.
 18. The process of claim 14 wherein the halogen is in para position.
 19. The process of claim 15 wherein the halogen is in para position.
 20. The process of claim 16 wherein the halogen is in para position.
 21. The process of claim 17 wherein the halogen is in para position.
 22. The process of claim 15 wherein the halogen is bromine.
 23. The process of claim 17 wherein the halogen is bromine.
 24. The process of claim 19 wherein the halogen is bromine.
 25. The process of claim 21 wherein the halogen is bromine.
 26. The process of claim 25 wherein the carrier is solid. 